A huge haul of elephant ivory seized in Uganda probably includes tusks stolen from government strongrooms last year, wildlife officials said Tuesday.

In November, Ugandan authorities discovered that more than a tonne (2,204 pounds) of impounded ivory had vanished from state vaults.

Police said Sunday that over 700 kilogrammes (1,543 pounds) of ivory -- worth almost $1.5 million on the black market -- and over two tonnes (4,409 pounds) of skins from pangolin, a scaly anteater, were uncovered in boxes at Uganda's main Entebbe airport as they were being exported to Amsterdam.

"Some of them bore markings of rectangular cuttings used by our veterinary doctors to get specimen for the DNA tests," Uganda Wildlife Authority (UWA) spokesman Jossy Muhangi told AFP.

Three people including the clerk at the airport, a customs officer and the driver of a truck that delivered the cargo have been arrested.

"The discovery of some pieces in the Entebbe consignment, (and) the arrest of the driver and the cargo officers will give us some clue on who the culprits are," Muhangi added.

Raw ivory sells for around $2,100 a kilogramme at markets in China, according to the campaign group Save the Elephants.

The scaly-skinned pangolin is used in traditional medicine in China, with exploding demand in Asia making it one of the most trafficked mammals in the world.

The tusks, which appeared to be have been recently hacked from elephants, were cut into several pieces, and it was not clear how many animals had been killed for them.

Poaching has risen sharply across Africa in recent years fuelled by rising demand in Asia for products coveted for traditional medicine or as status symbols.

Uganda is a key transit country for the illegal trade in ivory, especially from Congo's huge central African forests.